Abstract: Chitosan was used as carrier and glutaraldehyde was used as cross-linking agent for the immobilization of papain.The immobilized conditions and stability of immobilized papain as well as its application in extraction of burdock polysaccha-ride were studied.The results showed that optimal conditions of immobilization of papain were 2.5% chitosan concentrations,0.3 g papain/g carrier,6 h times,15 ℃ temperature,pH7.5.The recovery activity of immobilized papain was 38.98%.The optimal conditions of extraction of burdock polysaccharide were 1:20 ratios of solid to liquid(W/V),pH6.5,60 ℃temperature,8h hydrolyzed times,added 1.8g immobilized papain/g carrier.The extracting ratio of burdock polysaccharide was 11.04%.The activity of immobilized papain remained more than 50% after repeated 5 times.

Key words:  , chitosan； immobilization； papain； burdock polysaccharide；